100% agree. I was not implying in any way that Posey belongs in the same convo as Bench (or Fisk, as I consider the two of them the best ever by a mile…. Not counting Gibson, of course).
As for the importance of Posey vs the importance of Bench, that is hard to judge. Those Reds teams were stacked with HOFers, while the Giants only had a bunch of HOVGers.
Those Giants teams were bizarre. Aubrey Huff had a crappy 2009 but has one of the best seasons of his career in 2010 before retiring several years later. They also had a 32-year-old Andres Torres that was out of the league from 2006-2008 put up a 5+ WAR season.
The 2012 team got a 157 OPS+ from Melky Cabrera, who had a career 103 OPS+. They had Ryan Vogelsong, who was a mediocre major leaguer from 2000-06 and hadn't pitched in the majors from 2007-10 put up a 3.05 ERA in 369.1 IP in 2011-12. Sure enough, he ended up being a postseason hero with a 1.09 ERA in 24.2 IP.